<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box {
      display: flex;
      /* 自动换行 */
      flex-wrap: wrap;
      width: 1000px;
      height: 500px;
      border: 3px solid pink;
      margin: 100px auto;

    }

    .box div {
      width: 250px;
      height: 200px;
      background-color: skyblue;
    }
  </style>
</head>

<body>
  <div class="box">
    <div>1</div>
    <div>2</div>
    <div>3</div>
    <div>4</div>
    <div>5</div>
    <div>6</div>
    <div>7</div>
    <div>8</div>
  </div>
</body>

</html>